Yazarlar: Cenan Özkaya, Fikret Tulumtaş, M. Dicleli, Nuri Çelebi
Yayın Yeri : Bridge Maintenance, Safety, Management and Life-Cycle Optimization – Frangopol, Sause & Kusko (eds)
Yayın Yılı : 2010
Açıklama :
In this paper, the seismic isolation (SI) design of the Sakarya-II viaduct located within 300 meters of the North Anatolian fault in Turkey is studied. Strong near-field characteristics such as directivity and liquefaction are expected due to soft soil conditions under the scenario earthquake. A hybrid SI-system is chosen for the bridge. The hybrid SI-system consists of four natural and two lead-rubber bearings supporting the six steel-girders at each substructure. Lead cores in the lead-rubber bearings are designed to have an overall characteristic strength equal to 10% of the superstructure weight. This large characteristic strength is intentionally chosen to limit the isolator displacements under near-field effects. Furthermore, the supplementary four natural rubber bearings over each substructure provided additional stiffness to achieve a small post elastic period to deflect the earthquake input energy transferred through the underlying soft soil and to limit the isolator displacements under near-field effects. Nonlinear time history analyses of the viaduct with hybrid SI system have revealed that the hybrid SI-system reduced the sensitivity of the bridge response to the characteristics of the near-fault earthquake and liquefaction.